SmartJacket Water Heater Blanket Insulation System, Energy Star Certified, R value-7.1 WATER HEATER BLANKET - SmartJACKET is a unique system that creates a space between the blanket and the water heater tank to achieve better results. IMPROVE EFFICIENCY - Improve the efficiency of 95% of all water heaters in use today, Reduce Heat loss Up to 40 %. SIMPLE INSTALLATION - Easy to install and easy to clean, fits gas or electric water heaters. ENVIRONMENTALLY FRIENDLY - Non-toxic, non-carcinogenic. Contains no fiberglass. PROTECT YOUR INVESTMENT - Prolongs the life of your water heater, Fits all 20 to 60 gallon tanks.